Furniture wax, like car wax, provides very limited protection against chemical assault. It will help some, especially if you get spills cleaned up quickly. Mostly it's to make the wood look prettier. What really determines a piece of furniture's durability is the finish. Do you know what kind of finish is on the piece?
Knowing that a piece's finish is "stained walnut" is kind of like knowing that a car's finish is "red". Doesn't tell you much. You have to know what type of finish it has, shellac, oil based varnish, tung oil, lacquer, urethane varnish, etc. All have different tolerance for various kinds of abuse.
An awful lot of commercially built furniture comes with polyurethane finishes these days. I would think that something that was designed specifically for use as a bar would have a pretty tough finish on it. If it was custom piece ask the builder what he used.
PC.